The charts are more than just pretty, though, when the data is examined more closely; patterns start to emerge. And the patterns are interesting, to say the least. Look at the charts below, for example, and note that the yellow bar is almost universally the longest in each grouping.

So, why is it that Delta Air Lines appears to be consuming more fuel per hour than its competitors on nearly every aircraft type (only on the 752s is it lower than some competition)? Why is US Airways generally nipping at Delta’s heels in that race? And why is United Airlines almost universally the most efficient on a fuel per hour basis? Where both Delta and United operate the same aircraft type the data suggest that United flies using, on average, between 6% and 34% less fuel per hour. It is almost enough to cast some skepticism about the validity of the numbers (I’m quite certain the VX A319 number is wrong, but the others are reasonable enough, despite the wide spread).

Also of note, United’s 787-8 is consuming about the same fuel per hour as the 767-300ERs. But the Dreamliners carry about 25% more passengers so the overall efficiency realized there is significant. Similarly, it is easy to see why United wants to use the 737-900ER as much as possible on domestic routes versus the 757-200. The former consumes ~850 gallons per hour while the latter is at 1050; switching to the new planes means millions in savings because of that. (The domestic numbers are not in the chart here; I pulled them out separate to avoid confusing the overall analysis.)

Lots of data to look at, and almost as many questions as answers once it is parsed and sorted.

13 Responses

aside from the huge outliers, there are a lot of factors which could influence the data:
1) aircraft factors: age of aircraft, engine choice, seating configuration, IFE weight, winglets or engine PIPs
3) route factors – stage length, altitude, loads, etc.
As for time, not sure if they are only looking at cruise, flight, or gate to gate.

All the times are gate-to-gate which penalizes an airline for longer taxi times but it is hard to believe that over a full calendar quarter one is that much worse than the others.

I’m sure all of these other factors come into play, but it is surprising to me that the impact can be up to 30% on some aircraft. That seems quite a high spread. Even on the 744s where the overall mission profile is very, very similar the UA/DL fuel burn rates are not.

You say
“But the Dreamliners carry about 25% more passengers so the overall efficiency realized there is significant. Similarly, it is easy to see why United wants to use the 737-900ER as much as possible on domestic routes. The former consumes ~850 gallons per hour while the latter is at 1050; switching to the new planes means millions in savings because of that.” I think you mean to compare the 737-900 to the 757-200 but I think you forgot to actually state what the “latter” aircraft you were referring to is.

“United’s 787-8 is consuming about the same fuel per hour as the 767-300ERs. But the Dreamliners carry about 25% more passengers so the overall efficiency realized there is significant. ”
A 787-8 is a Dreamliner. He is comparing a 787 to a 767.

Age of the airplane and the engine will generally contribute 1-2% difference in fuel burn… Long taxi and short taxi will most likely be balance out over time, as I am sure most of those carries flies to very similar destination with their own respective delays at their own hubs… Finally the most significant contribution to this will be stage length of each sector, as it cost fuel to carry fuel, the longer then stage length of the average sector, the more fuel per hour that airline will burn. So from the looks of it, I will say the average stage length of Delta operations is longer than the average at United.